Serum - 1.0 ml preferred, 0.5 ml minimum
Collect in a red top tube, separate serum promptly OR collect in a serum separator tube, spin and send "as is"
Serum IgG antibody is endpoint titered by limiting dilutions using the AGID technique against the Meridian "F" antigen.
Antibodies direct again the "F" antigen indicate active or recent past (up to 1 year) infection. The ID test is usually positive within four weeks after infection and remains positive throughout the clinically active disease.